Monoclonal antibodies that recognize the P fimbriae F71, F72, F9, and F11 from uropathogenic Escherichia coli

Abstract

The Escherichia coli P fimbriae F71, F72, F9, and F11 from four cloned strains were purified, and polyclonal antisera were raised in rabbits. Cross-reactions of these antisera with eight different cloned and purified fimbriae were measured in an enzyme-linked immunosorbent assay. These antisera showed a reaction with the homologous fimbriae and also with most heterologous fimbriae. Monoclonal antibodies (MAbs) directed against the same four native fimbriae were produced by the fusion of spleen cells from immunized BALB/c mice with SP2/0 myeloma cells. The resulting four series of MAbs were also screened in an enzyme-linked immunosorbent assay with eight different cloned and purified fimbriae. Four different F71 hybridomas produced MAbs which recognized only epitopes on F71 fimbriae. Two F72 MAbs recognized epitopes on F72 and F9 fimbriae, whereas another F72 MAb recognized an epitope on only F72 fimbriae. Three MAbs raised against F9 reacted only with epitopes on F9 fimbriae. Six MAbs against F11 fimbriae could be divided into two groups: on the one hand two MAbs recognizing F11, pyelonephritis-associated pilus, Pap, and F72 fimbriae and on the other hand four MAbs recognizing F11 and "Clegg" fimbriae. None of the MAbs reacted with 1A or 1C fimbriae. In a hemagglutination inhibition assay it was shown that none of the MAbs produced inhibited the adhesive properties of homologous cloned strains.